#include <stdio.h>
#include <stdlib.h>

int main()
{
    char *who = getenv("USER");
    if(who == "root")
    {
        //有权限，执行相关代码
        printf("user:%s\n",who);
        printf("user:%s\n",who);
        printf("user:%s\n",who);
    }
    else
    {
        printf("权限不足\n");
    }
    return 0;
}